# spf (blogs) — RSS Amplifier Recent posts from the 2 feeds in the RSS Amplifier directory that cover spf. Page: Feed: --- ## [BIMI Certificates and Domains](https://www.wordtothewise.com/2026/05/bimi-certificates-and-domains/) _2026-05-29 · Word to the Wise_ BIMI is the protocol that gives you little images and blue checkmarks alongside your message in the inboxes of some mail clients. ## [The new DMARC is here](https://www.wordtothewise.com/2026/05/the-new-dmarc-is-here/) _2026-05-20 · Word to the Wise_ DMARCbis the new DMARC is finally here. RFC 9989 - Domain-Based Message Authentication, Reporting, and Conformance (DMARC) RFC 9990 - Domain-Based Message Authentication, Reporting, and Conformance (DMARC) Aggregate Reporting RFC 9991 - Domain-Based Message Authentication, Reporting, and Conformance (DMARC) Failure Reporting It’s not DMARCbis any more, it’s just DMARC. ## [DKIM2, Asynchronous Bounces and VERP](https://www.wordtothewise.com/2026/04/dkim2-asynchronous-bounces-and-verp/) _2026-04-27 · Word to the Wise_ This is just expanding on some of the points Laura made last week. ## [DKIM2: What it means for the future of email](https://www.wordtothewise.com/2026/04/dkim2-what-it-means-for-the-future-of-email/) _2026-04-23 · Word to the Wise_ Table of Contents Introduction What is it? OK, but really, what is it? OK. Why? Current Status ESPs Take Note Next Steps Conclusion Introduction After years of stagnation in email authentication protocol development we have a new player entering town. The protocol is DKIM2 and it’s in active development over at the IETF. If you want to see the sausage being made, you can visit the IETF… ## [The spam folder and opens](https://www.wordtothewise.com/2026/04/the-spam-folder-and-opens/) _2026-04-09 · Word to the Wise_ Open Tower Bridge, London 2022, ©Laura Atkins There’s a post getting a lot of traction in my LinkedIn feed from someone spreading misinformation about open rates. A bunch of deliverability colleagues have weighed in and pointed out some of the mistakes, but there’s one very big mis-statement I haven’t seen anyone correct. \[1\] ## [SPF ?all](https://www.wordtothewise.com/2026/03/spf-all/) _2026-03-20 · Word to the Wise_ I was updating my SPF library and discovered that the example code snippets didn’t work any more, as at some point in 2024 AOL switched their SPF record from “(lots of stuff\]) ~all” to “(lots of stuff) ?all”. Nothing particularly surprising, folks change their setups occasionally. I updated the example code to expect a neutral response rather than softfail and all the… ## [Upcoming webinar on Gmail and inbox signals](https://www.wordtothewise.com/2026/03/upcoming-webinar-on-gmail-and-inbox-signals/) _2026-03-13 · Word to the Wise_ I’m thrilled to announce I’m sitting down at the beginning of April to talk about inboxing in 2026. ## [Recent Writings and Events](https://www.wordtothewise.com/2026/02/recent-writings-and-events/) _2026-02-19 · Word to the Wise_ I don’t know about you, but we’re more than 6 weeks into 2026 and I can’t figure out where all the time has gone. It’s been a much busier January than I’m used to. I’ve been working on a lot, including a project I’ve been trying to get off the ground for a while. I’m really excited it’s finally taking shape and I hope to be able to share it… ## [Not Business as Usual](https://www.wordtothewise.com/2026/01/not-business-as-usual/) _2026-01-26 · Word to the Wise_ I don’t know what to say about what’s happening in the US, but I know I can’t stay silent, either. I don’t have anything inspiring to say here. I just cannot keep silent and pretend it’s all business as usual. I’m saddened, I’m horrified, I’m sick about what the government of the US is doing to citizens and non-citizens alike. ## [Don't send customer-generated content](https://www.wordtothewise.com/2026/01/dont-send-customer-generated-content/) _2026-01-19 · Word to the Wise_ I just got this email: SPF is valid. It passes DKIM for zoom.us. ## [Dissecting Series A Rounds (Sponsored)](https://crawlproof.com/a/dlAa8LhlM3Wu) _2026-01-19 · **Sponsored**_ Two real Series A cases: timelines, investor sequencing, and common founder mistakes. ## [IPv4 and IPv6](https://www.wordtothewise.com/2025/12/ipv4-and-ipv6/) _2025-12-16 · Word to the Wise_ There are two Internets There are two separate Internets, the Old Internet and the New Internet. They might travel over the same ethernet cables or wifi, but they’re quite separate and rarely directly interact with each other. ## [Let's Talk Reengagement](https://www.wordtothewise.com/2025/12/lets-talk-reengagement/) _2025-12-05 · Word to the Wise_ I appear to have written a lot about about re-engagement on the Email Geeks slack channel the last few days. The problem with slack is it’s not great at archiving or keeping information in an accessible, searchable manner. So, I’ve pulled together the answers, rearranged it, made it slightly more coherent and a little less stream of consciousness, so I can reference this when the topic… ## [Folding email headers](https://www.wordtothewise.com/2025/11/folding-email-headers/) _2025-11-21 · Word to the Wise_ Why are my DKIM signatures failing at Microsoft? There are several reasons why your DKIM signatures might be failing at Microsoft, but perhaps not at other major providers. Many of them are triggered by sending mail that’s “badly structured” in some way. This is one of them. ## [Undisclosed Recipients](https://www.wordtothewise.com/2025/11/undisclosed-recipients/) _2025-11-14 · Word to the Wise_ To: Undisclosed recipients:; Very occasionally you’ll see something in the To: header of an email that isn’t the email addresses you expect, instead it’s the string Undisclosed recipients:;. What does that mean? ## [B2B Spam: Strapi, Unstructured and Reo](https://www.wordtothewise.com/2025/10/b2b-spam-strapi-unstructured-and-reo/) _2025-10-17 · Word to the Wise_ About a year ago I was rebuilding this blog, moving it from WordPress to … something else. I evaluated several content management systems for that, and one of them was Strapi. ## [Changes happen, even if you don't keep up](https://www.wordtothewise.com/2025/09/changes-happen-even-if-you-dont-keep-up/) _2025-09-24 · Word to the Wise_ I cannot count the number of times I hear someone complain that they didn’t change anything and now their email isn’t delivering and why did this happen all of a sudden and how can they be blocked now when they weren’t blocked 3 months ago. Nothing changed, so why all of a sudden is mail failing? ## [Laposte.net will be requiring all email be authenticated](https://www.wordtothewise.com/2025/09/laposte-net-will-be-requiring-all-email-to-be-authenticated/) _2025-09-04 · Word to the Wise_ Starting on September 9th laposte.net will begin requiring email to have valid, aligned authentication. Mail that isn’t authenticated will start to be delivered to the spam folder or rejected at delivery time. ## [Yahoo's mailboxes are full](https://www.wordtothewise.com/2025/08/yahoos-mailboxes-are-full/) _2025-08-29 · Word to the Wise_ 552 5.2.2 This message could not be delivered because the recipient’s mailbox is full. Please try again later or contact the recipient directly. See https://senders.yahooinc.com/smtp-error-codes#mailbox-full for more information ## [Deliverability rules](https://www.wordtothewise.com/2025/08/deliverability-rules/) _2025-08-18 · Word to the Wise_ Hot Take: Anyone who has to know exactly what the rules are for inbox delivery is trying to figure out how close they can get to violating the rules without negative consequences. Senders that comply with the spirit of the rules don’t care what the specifics of the rules are. ## [Message-ID Syntax](https://www.wordtothewise.com/2025/08/message-id-syntax/) _2025-08-12 · Word to the Wise_ Our friends in the Email Geeks slack have recently started seeing sporadic rejections due to invalid Message-ID headers. ## [Follow Releases, Get Reminders (Sponsored)](https://crawlproof.com/a/JBtyD4wIJgj8) _2025-08-12 · **Sponsored**_ Follow a genre or a name and receive reminders on release day — free. ## [Don't make your DNS TTLs too short](https://www.wordtothewise.com/2025/07/dont-make-your-dns-ttls-too-short/) _2025-07-21 · Word to the Wise_ DNS is a complex, distributed database built on top of an unreliable network that spans the world. ## [Gmail says your unsubscribe "Needs work"](https://www.wordtothewise.com/2025/07/gmail-says-your-unsubscribe-needs-work/) _2025-07-11 · Word to the Wise_ Needs work? We’ve written about RFC 8058 “one-click” unsubscribe and how it’s part of the requirements for bulk senders wanting to deliver mail to the major consumer mailbox providers. ## [About that cold email](https://www.wordtothewise.com/2025/06/about-that-cold-email/) _2025-06-23 · Word to the Wise_ Over the years I’ve made the decision to stop working with certain types of senders. Most recently it’s been the decision to not work with companies sending cold email. I even wrote a blog post back in 2018 about my frustration with clients who were upset their cold email was going to the spam folder. That was the beginning of the end for cold emailers as clients. I did continue to try… ## [You can't DKIM sign a cabbage](https://www.wordtothewise.com/2025/06/you-cant-dkim-sign-a-cabbage/) _2025-06-18 · Word to the Wise_ The DKIM specification and implementations of DKIM signing and validation code make some unstated assumptions about the environment they’re running in. ## [The Challenges of B2B deliverability](https://www.wordtothewise.com/2025/06/the-challenges-of-b2b-deliverability/) _2025-06-03 · Word to the Wise_ Tomorrow Laura will be giving a webinar as part of the MarketingProfs Summer series. She’ll be speaking specifically about Rising to the Challenge of B2B Deliverability. This talk discusses the fundamental differences between business and consumer mailboxes and how we can’t just apply consumer mailbox deliverability advice to a business environment. ## [SWAKS on macOS](https://www.wordtothewise.com/2025/05/swaks-on-macos/) _2025-05-21 · Word to the Wise_ SWAKS is my favorite SMTP debugging tool. A new SMTP server I’m building loses pipelining synchronization when connecting via TLS, and I’m sure the bug will be simple to spot if I can send some test messages in to it and watch the sequence of commands. SWAKS is perfect for that. ## [Deliverability Summit Amsterdam](https://www.wordtothewise.com/2025/04/deliverability-summit-amsterdam/) _2025-04-02 · Word to the Wise_ We’ll be speaking at the Deliverability Summit in Amsterdam on April 24th and 25th. ## [Google and Alignment Update](https://www.wordtothewise.com/2025/03/google-and-alignment-update/) _2025-03-28 · Word to the Wise_ Earlier this month, I published a post about some changes with how Google is displaying information related to authentication in their “View Original” page. There’s one condition I apparently didn’t report and it brought up a question earlier today. ## [What Spamtraps Tell Us](https://www.wordtothewise.com/2025/03/what-spamtraps-tell-us/) _2025-03-14 · Word to the Wise_ Many blocklists use spamtraps to detect poor sending practices and will cite spamtrap hits as the reason for the blocks. Senders legitimately fear spamtraps showing up on their lists because of this. If spamtraps weren’t used by blocklists no one would really care about them. They’re just another kind of bad address. ## [Do spamtraps exist?](https://www.wordtothewise.com/2025/03/do-spamtraps-exist/) _2025-03-13 · Word to the Wise_ One of the folks on the Email Geeks slack asked me a question last week that I thought was really insightful and has a somewhat nuanced answer. ## [Privacy-first AI-native browser (Sponsored)](https://crawlproof.com/a/62ZwzmZZOrDw) _2025-03-13 · **Sponsored**_ No telemetry or ads — built on Ungoogled Chromium with a built-in AI sidebar and CLI. ## [Google, Alignment and DMARC](https://www.wordtothewise.com/2025/03/google-alignment-and-dmarc/) _2025-03-11 · Word to the Wise_ Google has been making a number of changes to their systems over the last few weeks. Folks are seeing a lot of changes in Google postmaster tools and they’re seeing changes in how Google is displaying headers in the “show original” tab. ## [Setting up a smarthost](https://www.wordtothewise.com/2025/02/setting-up-a-smarthost/) _2025-02-28 · Word to the Wise_ We run most of our own network services – inbound and outbound email, DNS and web presence. We run separate services for inbound and outbound email to give us more flexibility in how we set things up. ## [How to choose an ESP based on deliverability](https://www.wordtothewise.com/2025/02/how-to-choose-an-esp-based-on-deliverability/) _2025-02-10 · Word to the Wise_ Despite what a lot of SEO slop will try and tell you there’s no way to measure deliverability performance across multiple ESPs in any way that’s meaningful. ## [Don’t add your domain to the Public Suffix List](https://www.wordtothewise.com/2025/02/dont-add-your-domain-to-the-public-suffix-list/) _2025-02-05 · Word to the Wise_ (At least, not if you ever intend to use it for email. It might break the domain for email, maybe forever.) ## [Are Complaints Weighted?](https://www.wordtothewise.com/2025/01/are-complaints-weighted/) _2025-01-31 · Word to the Wise_ I’ve been doing a lot of my question answering over on the Email Geeks slack and have decided to bring some of the answers over here. Today’s question: ## [Diagnosing Hard Bounces](https://www.wordtothewise.com/2025/01/diagnosing-hard-bounces/) _2025-01-28 · Word to the Wise_ A very short post about diagnosing hard bounces, because I’ve had to give the same advice to a dozen folks over the past few months. ## [Effects of the Yahoo and Google Changes](https://www.wordtothewise.com/2025/01/effects-of-the-yahoo-and-google-changes/) _2025-01-23 · Word to the Wise_ In October 2023, Yahoo and Google announced new standards for sending bulk mail to their systems. For bulk senders these changes included requiring aligned authentication and publishing a DMARC record and complying with the List-Unsubscribe RFC. The ISPs also formally announced complaints must stay below a threshold of 0.3%. At the time of the announcement, they said enforcement would start in… ## [Stop using Entrust for your BIMI Certificates](https://www.wordtothewise.com/2024/12/stop-using-entrust-for-your-bimi-certificates/) _2024-12-31 · Word to the Wise_ In July I talked about how Entrust was mistrusted by, well, pretty much everyone due to a years long series of security and trust violations. ## [Tracking link maths](https://www.wordtothewise.com/2024/12/tracking-link-maths/) _2024-12-10 · Word to the Wise_ How long does a tracking link need to be? ## [There’s text and then there’s text](https://www.wordtothewise.com/2024/11/theres-text-and-then-theres-text/) _2024-11-28 · Word to the Wise_ If you want to send someone an email with some text in it there are quite a few different ways you can do it. The main differences are the ways the text is packaged up in MIME entities to be sent. ## [Your bounce classification is a bit rubbish](https://www.wordtothewise.com/2024/11/your-bounce-classification-is-a-bit-rubbish/) _2024-11-26 · Word to the Wise_ When a mailbox provider rejects or defers an email it sends back a message explaining why. ## [Do we care about SPF alignment?](https://www.wordtothewise.com/2024/11/do-we-care-about-spf-alignment/) _2024-11-22 · Word to the Wise_ SPF and DKIM are the two main ways we associate a domain name with a stream of email in an authenticated way. We can choose the DKIM signing domain fairly freely – we can choose any domain or subdomain we control and put it in the d= field of the DKIM signature. But our choice for the SPF domain is more constrained. ## [Comparing DKIM keys](https://www.wordtothewise.com/2024/11/comparing-dkim-keys/) _2024-11-20 · Word to the Wise_ Sometimes we have a client who has done something wrong when setting up authentication. Their DKIM signing fails due to something being wrong with the public key they’ve published. ## [The Future of Deliverability](https://www.wordtothewise.com/2024/10/the-future-of-deliverability/) _2024-10-30 · Word to the Wise_ There always seems to be appetite from folks to read the tea leaves and follow up with predictions about what the future holds. I mean, how many folks in the US are obsessively refreshing polls for the last few weeks? (American’s: don’t forget to vote on Tuesday!) ## [No, Gmail did not just break all open tracking](https://www.wordtothewise.com/2024/08/no-gmail-did-not-just-break-all-open-tracking/) _2024-08-29 · Word to the Wise_ I was avoiding commenting on the email open tracking bad take that seems to be going viral round the more gullible corners of LinkedIn. ## [DNS Failures](https://www.wordtothewise.com/2024/08/dns-failures/) _2024-08-28 · Word to the Wise_ We use DNS a lot in email, particularly for authentication, so diagnosing why DNS isn’t returning what we expect it to is a pretty common challenge. And DNS responses aren’t exactly the clearest thing to understand.